The Vienna Metro

Here is a list of the most important extensions to the metro network that will not be built in the near future (see also diagram above):

• U1A (Karlsplatz-Matzleinsdorfer Platz) und U1B (Praterstern-Messe): The original metro concept from the 1970s included branches for each line, such as line U1A under the Wiedner Hauptstrasse to Matzleinsdorfer Platz, using part of the existing tram tunnel in this area. However, based on experience with the conversion of the tram tunnel for line U2 and the failed experiment with branch line U2/4, this project was abandoned. The second branch, line U1B will now be built as part of the extension of line U2, although the third rail installed at Praterstern station, which had been built in preparation for line U1B, will not be used by the U2 extension.

• U7 (Floridsdorf-Kagran-Aspern): This line appeared on some of the early plans in the 1960s, but was never seriously considered for implementation in the foreseeable future.

• U6A (Längenfeldgasse - Südbahnhof): This project, which was to use the tram tunnel along the southern Gürtel, was also abandoned when it became obvious that the existing tram network in the area was more efficient that converting the tunnel to full metro.

• U2-Northwest (Landesgericht-Währing): The original plan for line U2 was to build the line from Karlsplatz to Währing. For financial reasons, only the section between Karlsplatz and Landesgericht was built, with an option to build the remaining section later. This is, however, not very likely to happen.

• U4A a.k.a. U5 (Landesgericht-Hernals): This line was originally planned as a branch of line U4 from Schottenring to Hernals. When the concept of branch lines was abandoned in the 1980s, it was instead referred to as line U5. Only the section between Schottenring and Landesgericht was built and is now operated as part of line U2. The remainder of the line might now be built in a different manner, leading south instead of east. For more details about why there is no line U5, see The Tragic Story of Line U5.

• U4-West (Hütteldorf-Auhof): This extension was planned in the early 80s, but when a huge real estate project in that area failed to gain permission, it was abandoned as well.